Method and apparatus for performing cell reselection in wireless communication system

Abstract

A method and apparatus for performing cell reselection in a wireless communication system is provided. A user equipment (UE) in an idle mode camps on a second cell, and receives reselection information for dual connectivity, which indicates cell reselection to a first cell or cell reselection to a frequency of the first cell, from the second cell. If the UE supports dual connectivity, the UE performs cell reselection based on the received reselection information for dual connectivity.

What is claimed is: 
     
       1. A method for performing, by a user equipment (UE), cell reselection in a wireless communication system, the method comprising:
 camping on a second cell; 
 receiving a threshold from a network; 
 receiving reselection information for dual connectivity, which indicates cell reselection to a first cell or the cell reselection to a frequency of the first cell, from the second cell; and 
 if the UE supports dual connectivity and if a speed of the UE is lower than the threshold, performing the cell reselection to the first cell or to the frequency of the first cell based on the received reselection information for dual connectivity and the threshold. 
 
     
     
       2. The method of  claim 1 , wherein the UE is in an idle mode. 
     
     
       3. The method of  claim 1 , wherein the reselection information is received via system information. 
     
     
       4. The method of  claim 1 , wherein the reselection information includes a cell identity of the first cell. 
     
     
       5. The method of  claim 1 , wherein the reselection information includes a type of the second cell. 
     
     
       6. The method of  claim 5 , wherein the type of the second cell is one of a small cell, a pico cell, a femto cell, a closed subscriber group (CSG) cell, or a hybrid cell. 
     
     
       7. The method of  claim 1 , wherein the reselection information includes a type of the first cell. 
     
     
       8. The method of  claim 7 , wherein the type of the first cell is a macro cell. 
     
     
       9. The method of  claim 1 , wherein the first cell is a macro cell served by a master eNodeB (MeNB), and
 wherein the second cell is a small cell served by a secondary eNodeB (SeNB). 
 
     
     
       10. A user equipment (UE) in a wireless communication system, the UE comprising:
 a radio frequency (RF) unit for transmitting or receiving a radio signal; and 
 a processor coupled to the RF unit, and configured to:
 camp on a second cell; 
 control to the RF unit to receive a threshold from a network; 
 control to the RF unit to receive reselection information for dual connectivity, which indicates cell reselection to a first cell or the cell reselection to a frequency of the first cell, from the second cell; and 
 if the UE supports dual connectivity and if a speed of the UE is lower than the threshold, perform the cell reselection to the first cell or to the frequency of the first cell based on the received reselection information for dual connectivity and the threshold. 
 
 
     
     
       11. The UE of  claim 10 , wherein the UE is in an idle mode. 
     
     
       12. The UE of  claim 10 , wherein the reselection information is received via system information. 
     
     
       13. The UE of  claim 10 , wherein the reselection information includes a cell identity of the first cell. 
     
     
       14. The UE of  claim 10 , wherein the reselection information includes a type of the second cell.